A converging collimator is used to make the organ appear larger at the face of the crystal. The holes of converging collimators are focused toward the organ instead of parallel. The focal point is commonly located in the middle of the field of view (FOV). It is also possible to locate the focal point near the edge of the FOV. The collimator will then be so-called half converging.
When an enlarged FOV is needed, a converging collimator can be filled over. The collimator will then be so-called diverging. These are generally used for portable cameras with a smaller crystal.